Container and method for producing it



Aug. 5 1924. 1,504,194

E. D. TREANOR CONTAINER AND METHOD FOR PRODUCING IT Filed July 5, 1922Patented Aug. 5, 1924.

A main EDWARD D. TREANOR, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TOGENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CONTAINER AND METHOD FOR PRODUCING IT.

Application filed July 3, 1922. Serial No. 572,558.

T all whom it may concern Be it known that LEDWARD D. TREANoR, a citizenof the United States, residing at Pittsfield, county of Berkshire, Stateof Massachusetts, have invented new and useful Improvements inContainers and Methods for Producing Them, of which the following is aspecification. My invention relates to sheet metal con- 1 tainers and tomethods for producing them. The general object of the invention is toprovide an improved form of container with a corrugated sheet metal walland also to provide an improved method of corrugating a sheet metalblank toform the container wall. Corrugating the wall of a container isa common expedient and in some cases this feature is of advantage ingiving increased strength to the corrugated part. 2 This invention,however, is of particular advantage in connection with sheet metalcontainers or casings for electrical apparatus such as transformers. Theoperation of the apparatus causes heat to be generated, '2 thedissipation of which to the surrounding air is facllitated by theincreased surface exposure due to the corrugations.

A casing for electrical apparatus is often partially or completelyfilled with an insulating fluid in which the apparatus is immersed andit is therefore desirable or necessary to make such a casing fluidtight. For this reason, it is desirable that the casing wall have smoothupper and lower '35 edges to fit the contours of the top and base sothat these parts may be conveniently secured together by welding orotherwise to form fluid tight joints. One of the objects of theinvention, therefore, is to provide a 40 container or casing wall withcorrugations in such manner that they leave smooth upper and lower edgesfor attachment to the top and base. Other objects and advantages Wlllappear.

Qne form of container or casing which may be used for enclosingelectrical apparatus and which may be produced in accordance with thisinvention is shown in the accompanying drawing in which Fig. 1 is a 0view in elevation of the casing; Fig. 2 is a plan view of a section of asheet metal blank which has been partially formed to ,constitute thewall of the casing, and Fig. 3 is a sectional view on the line 3-3 ofFig. 2.

Like reference characters refer to similar parts 1n the differentfigures of the drawing. 'Lhe particular container shown in the drawingincludes a wall 1, top or cover 2, and base 3. The wall 1 has smoothupper and lower edges of some simple contour,

such as circular or elliptical, so as to be conveniently fitted to thecover 2 and base 3. Between these edges is a series of corrugations 4which serve to increase the surface e posure of the casing to thesurrounding an and thusto increase its efficiency in radiating heatwhich may be generated by electrlcal apparatus enclosed Within thecasing. The ends of the corrugations 4 are tapered off so that at leastno substantial part reaches the upper or lower edge of the wall 1 todistort them and make more difficult the fitting and attachment of thecover 2 or base 3.

In connection with the container or casing shown in the drawing, theinvention has to do .with the corrugated wall 1 and the method ofproducing it. The wall is formed from a sheet metal blank of equalheight. Oppositely disposed spaced notches 5 are formed by punching orotherwise in the upper and lower edges of this blank as shown in theleft hand part of Fig. 2 of the drawing. The corrugations 4 are thenpressed into the blank by means of suitable dies midway between thenotches 5 as shown in the right hand part of Fig. 2. The ends of thecorrugations 4 extend between and beyond the bases of the notches 5 butare gradually tapered and terminate-inside the outer edges of the blank.The notches 5 are widest at the edges of the blank and taper to sharppoints at their inner ends or bases 6. In forming the corrugations, theblank is necessarily shortened, the amount by which it is shorteneddepending upon the shape and depth of the corrugations. The

pointed bases of adjacent notches 5 are thus drawn toward each other. Byreason of the fact, however, that the corrugations terminate inside theedges of the blank, the edge sections between the outer ends of thenotches are not shortened or changed in length. The ends of thecorrugations begin to taper near the bases 6 of the notches 5 and theirdepth decreases toward the edges of the blank so that the shortening ofthe material of the blank between the bases 6 of the notches and theedges of the blank is of maximum amount between the bases 6 of thenotches. This shortening decreases gradually until along the edges ofthe blank the material between the outer ends of the notches is notshortened or changed appreciably in any way except that these edgesections between the outer ends of the notches are drawn near togetherto form substantially smooth continuous edges. The shape of the sides ofthe notches is so designed with respect to the tapering of the adjacentends of the corrugations that they will be drawn into approximatelystraightlines close together and preferably perpendicular to the edgesof the blank as shown in the right hand part of Fig. 2. During theforming of the corrugations, the edges of the notches remain in theoriginal plane of the blank metal sheet and the adjacent metal is forcedto flow in this plane to straighten the curved edges of the notches andto bring them together or substantially so. When the shape of thedesired corrugation is known, the shape of the side edges, the depth andthe width of the outer ends of the notches may be calculated with asufficient degree of approximation or the shape and size of the notchesmay be easily determined by experiment.

After the original blank has been notched and corrugated and the edgesof the notches drawn. near together, the seams or joints formed by theseedges are welded or otherwise sealed to make't-hem tight. One or more ofthese corrugated sheets are bent to form the body 1 of desired size andof cylindrical or other desired form, the meeting edges being welded orotherwise sealed to make them tight. The top or cover 2 and .base 3 arewelded or otherwise secured and sealed to the corrugated wall 1 tocomplete the container.

The invention provides a container wall with the advantages incident toan increased heat radiating surface due to corrugating the wall and atthe same time its edges are not distorted by the corrugations but aresmooth and regular so that they may be easily and tightly fitted andsecured to the cover and base.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

per-ended corrugations terminating between said notches while the edgesof said notches remain in the original plane of said blank, the notchesbeing substantially closed by a flow of the met-a1 at their edges insaid plane, and shaping the corrugated sheet to form the container wall.

3. The method of producing a container, including the forming of spacednotches in an edge of a sheet metal blank, forming corrugations havingtapered portions between said notches while the edges of said notchesremain in the original plane of said blank, the notches having curvedside edges so formed as to be straightened and brought substantiallytogether by a flow of the adjacent metal in said original plane of theblank, and shaping the corrugated sheet to form the container wall.

4. The method of producing a container, including the forming of spacednotches in opposite edges of a sheet metal blank, forming corrugationshaving tapered portions extending between the notches at the op positeedges of said sheet while the edges of said notches remain intheoriginal plane of said blank, the notches having curved side edges soformed as to be straightened and brought substantially together by aflow of the adjacent metal in said original plane of the blank. andshaping the corrugated sheet to form the container wall.

5. The method of producing a corrugated metal sheet, including theforming of spaced notches in an edge of a sheet metal blank, and formingcorrugations having tapered portions extending between sai notches whilethe edges of said notches remain in the original plane of said blank,the notches being so formed as to be substantially closed. by a flow ofthe adjacent metal in said original plane of the blank, whereby acorrugated metal sheet is produced with a substantially smooth edge.

6. The "method of producing a corrugated metal sheet, including theforming of spaced notches in an edge of a sheet metal blank, formingcorrugations having tapered portions extending between said notches,while the edges of said notches remain in the original plane of saidblank, the notches having curved side edges so formed as to bestraightened and brought toward each other by a flow of the adjacentmetal in said original plane of the blank, and sealing said edges of thenotches together, whereb a corrugated metal sheet is produced wit asubstantially smooth edge.

7 The method of producing a corrugated metal sheet, including the forminof spaced notches in op osite edges of a s eet metal blank, and ormingcorrugations havin tapered portions extendin between sai notches atopposite edges 0 the sheet while the edges of said notches remain in theoriginal plane of said blank, the notches having curved side edges soformed as to be straightened and brought toward each other by a flow ofthe adjacent metal in said original plane of the blank, and sealing saidedges of the notches together, whereby a corrugated metal sheet isformed with substantially smooth edges.

8. A corrugated metal sheet produced by forming spaced notches inopposite edges of a sheet metal blank, forming corrugations terminatingbetween said notches while the edges of said notches remain in theoriginal plane of said blank, the notches being substantially closed bya flow of the ad acent metal in said plane of the original blank, andsealing the edges of the notches together, said corrugated sheet beingcharacterized by the sealed joints extending inwardly from its edges,terminating between the corrugations and located in the original planeof the blank from which the corrugated sheet was produced.

In Witness whereof, I have hereunto set my hand this 29th day of June1922.

EDWARD D. TREANOR.

